How to make a plane responsive to light?
I'm not 100% sure what you're going for, but I made this scene with just text, a plane, and a single spotlight (Material added to the text - everything else default). This is in cycles engine, and I left my world properties panel open so you can see the settings. If you cannot reproduce, you may be suffering from some kind of bug, but I think more likely you have too strong a world background (cycles picks up even faint World Lighting), or hidden lights. Look at the example and let me know what I'm missing: